Re: Battery charging oops!
Sorry, I have to disagree. That motor has Battery CD ignition (Motorola Amplifier). It will quit if the battery goes dead. Also, depending on whether or not it has the clipper circuit or replacement amplifier, disconnecting the battery while running will almost certainly destroy the rectifier and maybe the amplifier. The book is very specific about dirty or loose connections.
Check to see if the charging system is working by connecting a voltmeter across the battery terminals and see if the voltage increases after the motor runs awhile. It should, if it is working and you don't have a bunch of electrical accessories dragging it down.